Grounding fault transient current generator

Abstract

The invention discloses a grounding fault transient current generator, which comprises a grounding transformer, wherein the grounding transformer is connected with a system bus, a neutral point is led out of the grounding transformer to be connected with a monostable switch, the monostable switch is connected with the ground, the grounding transformer and the monostable switch are both fixed to a mounting bottom plate, four corners of the mounting bottom plate are in threaded connection with inserting rods, the outer rings, which are located on two sides of the mounting bottom plate, of the inserting rods are in threaded connection with locking nuts, the lower ends of the inserting rods are fixedly connected with deeply-buried blocks, the upper ends of the deeply-buried blocks are fixedly connected with lower sleeve plates, and outer rings of the inserting rods sleeve upper sleeve plates. According to the invention, the neutral point led out of the grounding transformer is connected with the monostable switch, when a system branch breaks down, the monostable switch is triggered, the reliability and safety of system power supply are improved, the manufacturing cost is low, and installation and operation are convenient. In addition, the deeply-buried blocks connected with the lower ends of the inserting rods and the lower sleeve plates and the upper sleeve plates which are connected with the inserting rods are deeply buried into the ground, so that the overall stability and the inclination resistance are improved.

Description

technical field [0001] The invention relates to the technical field of grounding safety electricity utilization, in particular to a ground fault transient current generator. Background technique [0002] In my country's 3-35KV medium-voltage transmission and distribution systems, most of them adopt the method of not directly grounding the neutral point, that is, the neutral point is not grounded or grounded through the arc suppression coil. The neutral point is not directly grounded. In the state of single-phase grounding, the system line voltage can still maintain three-phase symmetry without affecting the normal operation of electrical equipment. Therefore, the power supply reliability of the power transmission and distribution system using the neutral point not directly grounded method is much higher than that of the neutral point directly grounded power transmission and distribution system. This is the biggest advantage of the neutral point not directly grounded method, ...

AI Technical Summary

Problems solved by technology

However, according to years of operating experience and the development of medium-voltage power transmission and distribution systems in recent years, the non-direct grounding of the neutral point has also brought some problems to the medium-voltage power transmission and distribution system: the non-direct grounding of the neutral point is easy Occurrence of high-voltage oscillations, resulting in various overvoltages

This current is often much greater than the rated current of the voltage transformer, which will cause the iron core of the transformer to saturate, and the primary side current will increase sharply, blowing the fuse of the voltage transformer, or even burning the voltage transformer; it is difficult to determine the branch circuit where the single-phase ground fault occurs

However, when it is applied to the system where the neutral point is grounded through the arc suppression coil, the original line selection device based on the power direction line selection principle cannot be used.

[0004] The current solution is to connect the grounding transformer with the high-voltage thyristor trigger module to ground. When the ground fault occurs in the branch, the controller starts the high-voltage thyristor trigger module to commutate, thereby using the arc-suppression coil to eliminate the arc. The connection method is complicated and the cost is high, and the grounding transformer is easy to shake when it is placed for a long time in strong wind, which affects the use of the monostable switch

Images